But MP Charles Chong, whose Punggol Central ward, like all new estates, has seen an influx of foreigners, said the EIP now is too porous for a new generation of PRs.

‘The Indian community is pretty diverse. Sri Lankan is classified as Indian; Bangladeshi, Pakistani, northern Hindi-speaking Indians are all classified as Indians (for purposes of the EIP).’

If there are no sub-divisions, there could arise an enclave, say of Bangladeshis, all staying in the same block or precinct, he pointed out.

The same goes for mainland Chinese, Taiwanese or Chinese-Indonesians, who are all classified under ‘Chinese’.

Dr Lim argued, however, that the important distinction to make is not within ethnic classifications, but between Singaporeans and PRs. He said there are some floors of HDB blocks in his ward where more than half the residents are foreign.

They are a mix of nationalities. So although there is no ‘ethnic’ enclave as such, there is a high concentration of foreigners ‘to the point where Singaporeans feel threatened and become a minority’.

When that happens, then it becomes an issue, he said.

Dr Lim suggested a quota limiting the proportion of PRs in each precinct or block to the proportion of PR homeowners nationwide – or about 5 per cent.

MP Ho Geok Choo – who recalled a visitor describing her Boon Lay ward as being so cosmopolitan that it felt like being overseas – said a quota would help dampen excessive property prices. This would make it more difficult for PRs to artificially inflate prices in certain areas by all snapping up flats there, she said.

It would also assuage the concern of those Singaporeans who feel besieged in their neighbourhood by new sights and smells. On her house visits, every block throws up at least two or three Singaporeans who voice their concerns about this, she said.

But ultimately, a quota on home-buying may not make much of a difference.

Jurong GRC MP Halimah Yacob said more than 70 per cent of foreigners in her Bukit Batok East ward are renting. They rent in the area as it is close to their workplaces in the West.

While it is possible to envision an ethnic enclave of renters, ‘there’s nothing you can do (about where PRs rent)’, she said. The rental market is left entirely to free market forces.

Regardless, director of Dennis Wee Properties, Mr Chris Koh, foresees a big plus if a new quota is implemented: It would puncture the belief that some Singaporeans have that their flats can fetch a higher price if they sell them to PRs.

Sellers who hear that a certain nationality is prominent in the neighbourhood pressure agents to find such buyers, thinking it will mean more profits, he said.

‘If quotas are set… we can tell them, ‘We hit the quota max already and we have to be realistic about the price.”